decrypting a db column

Question

http://www.c-sharpcorner.com/uploadfile/chinnasrihari/data-encryption-and-decryption-in-sql-server-2008/

reffered above link

AS

BEGIN

SET NOCOUNT ON;

OPEN SYMMETRIC KEY SymmetricKey1

DECRYPTION BY CERTIFICATE Certificate1 WITH PASSWORD = 'Password';

SELECT CAST(DECRYPTBYKEY(kcode) as varchar(250))

FROM keycode

CLOSE SYMMETRIC KEY SymmetricKey1;

END

error

The private key password is invalid.

The key 'SymmetricKey1' is not open. Please open the key before using it